/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University.  All rights reserved.
 * 
 *
 *Redistribution and use in source and binary forms, with or without 
 *modification, are permitted provided that the following conditions are met:
 *
 *1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license;
 *2) All redistributions in binary form must reproduce the above copyright 
 * notice, this list of conditions and the disclaimer listed in this license in
 * the documentation and/or other materials provided with the distribution;
 *3) Any documentation included with all redistributions must include the 
 * following acknowledgement:
 *
 *"This product includes software developed by the Community Grids Lab. For 
 * further information contact the Community Grids Lab at 
 * http://communitygrids.iu.edu/."
 *
 * Alternatively, this acknowledgement may appear in the software itself, and 
 * wherever such third-party acknowledgments normally appear.
 * 
 *4) The name Indiana University or Community Grids Lab or NaradaBrokering, 
 * shall not be used to endorse or promote products derived from this software 
 * without prior written permission from Indiana University.  For written 
 * permission, please contact the Advanced Research and Technology Institute 
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202.
 *5) Products derived from this software may not be called NaradaBrokering, 
 * nor may Indiana University or Community Grids Lab or NaradaBrokering appear
 * in their name, without prior written permission of ARTI.
 * 
 *
 * Indiana University provides no reassurances that the source code provided 
 * does not infringe the patent or any other intellectual property rights of 
 * any other entity.  Indiana University disclaims any liability to any 
 * recipient for claims brought by any other entity based on infringement of 
 * intellectual property rights or otherwise.  
 *
 *LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO 
 *WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 *NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF 
 *INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS. 
 *INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS", 
 *"VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.  
 *LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR 
 *ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION 
 *GENERATED USING SOFTWARE.
 */
package cgl.narada.transport.ptcp.psocket.tools;

import java.util.Hashtable;

public class PTCPBuffer implements PTCPParameters {
  private Hashtable buffer_ = null;
  private int in_index_ = 0;
  private int out_index_ = 0;
  private int buffer_size_ = 0;
  private int number_of_streams_ = 0;
  private boolean exit_ = false;
  private boolean exit_array_[] = null;
  private boolean first_time_ = true;
  private boolean increase_performance_ = false;
  private String module_name_ = "PTCPBuffer: ";
  private int BUFFER_LIMIT = 11 * 1000 * 1000;
  private int packet_size_ = 0;

  public PTCPBuffer(int size) {
    initialize(size, false);
  }

  public PTCPBuffer(int size, boolean perfInc) {
    initialize(size, perfInc);
  }

  private void initialize(int size, boolean perfInc) {
    this.number_of_streams_ = size;
    this.buffer_size_ = size;
    this.increase_performance_ = perfInc;
    exit_array_ = new boolean[size];
    for (int i = 0; i < size; i++) {
      exit_array_[i] = false;
    }
    buffer_ = new Hashtable();

  }

  public synchronized void setExit(String name) {
    exit_array_[Integer.parseInt(name)] = true;
    exit_ = exit_array_[0];
    for (int i = 1; i < exit_array_.length; i++) {
      exit_ = (exit_ && exit_array_[i]);
    }
  }

  public synchronized void write(int index, Object o) throws
      InterruptedException {

    while (index != in_index_ || buffer_.size() == buffer_size_) {
      wait(250);
      if (exit_) {
        break;
      }
    }
    buffer_.put(String.valueOf(index), o);
    in_index_++;
    notifyAll();

  }

  public synchronized byte[] read() throws
      InterruptedException {

    int length = 0;
    int limit = out_index_ + buffer_size_;

    while (buffer_.size() < buffer_size_ && !exit_) {
      wait(150);
    }
    length = 0;

    for (int i = out_index_; i < limit; i++) {
      byte[] packet = (byte[]) buffer_.get(String.valueOf(i));
      if (packet != null) {
        length += packet.length;
      }
    }
    if (first_time_ && increase_performance_ && length < (BUFFER_LIMIT) &&
        length != 0) {
      buffer_size_ = (BUFFER_LIMIT) * number_of_streams_ / length;
      if (PTCPBuffer_Debug) {
        System.out.println(module_name_ + "buffer's adjusted size " +
                             buffer_size_);
        }
      packet_size_ = (int) (length / number_of_streams_);
        first_time_ = false;

      }    

    byte[] data = new byte[length];
    int start = 0;
    int end = out_index_;

    for (int i = end; i < limit; i++) {

      byte[] packet = (byte[]) buffer_.get(String.valueOf(i));
      if (packet != null) {
        if (PTCPBuffer_Debug) {
          System.out.println(module_name_ + "Packet " + i + " is received " +
                             packet.length);
        }
        System.arraycopy(packet, 0, data, start, packet.length);
        start += packet.length;
      }
      buffer_.remove(String.valueOf(i));
      out_index_++;
    }

    notifyAll();

    if (exit_) {
      if (data.length > 0) {
        return data;
      }
      else {
        return null;
      }
    }
    else {
      return data;
    }

  }

  public int getPacketSize() {
    return packet_size_;
  }

  public void setPacketSize(int packetSize) {
    this.packet_size_ = packetSize;
  }

}
